Data centers provide computational resources for executing applications. In one scenario, for example, an entity may instruct a data center to execute an application which it has developed. Further, the entity may specify a Service Level Agreement (SLA) which describes the particular manner in which the data center is requested to execute the application. The data center then executes the application on behalf of the entity, pursuant to the SLA, and returns the results of its computation to the entity. Typically the data center charges the entity a flat stated price for its services.
Present-day data centers receive all (or most) of their power from conventional utility power sources. The utility power sources deliver power to the data centers via an established power distribution infrastructure, commonly referred to as the power grid. As such, such utility power sources are referred to herein as on-grid power sources.
On-grid power sources have one or more shortcomings. First, on-grid power sources are expanding at a much slower rate than data center systems, and therefore will likely fail to fully meet the growing energy demands of these systems. Second, on-grid power sources are expensive and can be expected to markedly increase in cost over time. Moreover, governmental authorities can be expected to levy increasing “carbon taxes” on fossil fuels, increasing the costs of on-grid power sources which rely on these fuels. Third, on-grid power sources provide an expensive, invasive, and inefficient mechanism for delivering power to consuming entities. For example, the power distribution infrastructure typically uses various power transformation mechanisms in the delivery of power. These transformation mechanisms result in the loss of a certain percentage of power during distribution. Fourth, there are factors which limit the transfer power from one site to another. For instance, connectivity may not exist to transfer power from a first site (in which power is over-abundant) to a second site (in which power is lacking). And even if a connection exists, the transmission lines may place limits on the amount of power that can be transferred. These deficiencies are representative, rather than exhaustive; on-grid power sources may suffer from yet other shortcomings.
For these reasons, the utility companies and other actors have become increasingly interested in the prospect of renewable energy sources, such as wind power sources, solar power sources, etc. These renewable power sources are typically connected to the grid, where that grid has been historically associated with a conventional utility power source.
However, renewable power sources have their own respective shortcomings. Foremost, renewable power sources provide power which varies over time and location. In the terminology used herein, such power sources are said to be episodic. For example, a wind power source cannot provide power when the wind is not blowing and a solar power source cannot provide power when the sun is not shining. This characteristic is problematic for any entity which relies on these renewable power sources, such as utility entities and data centers. For instance, data center functionality attempts to deliver services to consuming entities in a timely fashion, whenever the consuming entities request the services. This goal is jeopardized by an episodic power source. Further, data center equipment is expensive, which means that is disadvantageous to leave part of the data center idle while adequate power is unavailable. Moreover, it is a time-consuming and expensive task to turn data center equipment on and off to accommodate episodic power availability.